Technical Abstract:
Representative adult MVM products (n>2 vitamins) reported in NHANES 2001-02 were chemically analyzed for 23 nutrients in order to evaluate the relationship between their label and analytical levels. A total of 240 MVM products were purchased based on commonly reported % Daily Value (DV) levels, repackaged and sent to an independent laboratory, along with control materials and blinded duplicate products. Most of the vitamins were analyzed by validated HPLC methods, while most of the minerals were analyzed by ICP. Laboratory results were statistically evaluated at each % DV level (n=6 products) and for each nutrient (typically n=18 or 24). Four nutrients had mean % difference from label values that were >20% above label and significantly different from label for at least 2 of the %DV levels analyzed: vitamin E (62%), thiamin (25%), selenium (24%) and vitamin B6 (23%). For iron, niacin, zinc, vitamin C, phosphorus, potassium and manganese, the mean % difference from label and standard deviation were both less than 10%, indicating that the analytical results for these nutrients in MVM products were consistently close to labeled levels. Results were more variable for the other vitamins and minerals studied. These data will be combined with results from an on-going analytical study of adult MVMs (n>9 vitamins) to evaluate nutrient variability for an analytically verified DSID. Funded by USDA & ODS/NIH Y1CN5010